Organic disulfide polymers are a class of important industrial compounds used commercially, for example, in battery applications and in high pressure lubricant applications.
Organic disulfide polymers can be prepared by polycondensation of a dihalide monomer with sodium disulfide in an aqueous solution. A trihaloalkane such as, for example, trichloropropane can also be added to the reaction medium to provide some degree of crosslinking of the disulfide polymers. However, this polycondensation process must be carried out in a suspension and the polymer thus-produced must be separated from the by-product sodium halide salts.
Organic disulfide polymers can also be prepared by oxidative polymerization of dithiols. For example, Japanese Application 49-104784 discloses the reaction of 1,2-ethanedithiol with oxygen in the presence of specific catalysts. The oxidation of 1,2-ethanedithiol can also be carried out with a halogen or hydrogen peroxide. However, these oxidative polymerization processes have some disadvantages. For instance, an oxidative polymerization using hydrogen peroxide is very exothermic and addition of hydrogen peroxide must therefore be slow. There is therefore an ever-increasing need to develop a better process for the preparation of an organic disulfide polymer.